diff --git a/osbase/socksproxy/protocol.go b/osbase/socksproxy/protocol.go
index d920099..0d5d133 100644
--- a/osbase/socksproxy/protocol.go
+++ b/osbase/socksproxy/protocol.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package socksproxy
 
 import (